Only update runtime maintenance-packages dependencies to latest when …

…not in source-build.

Without this workaround, the deps flow from runtime to sdk will get blocked by roslyn because that
repo will downgrade the package version.

Roslyn cannot immediately get these same dependencies updated because msbuild will fail to find them.

MSBuild needs to get these package versions updated before all other repos.

eng/Versions.props

@@ -79,6 +79,28 @@
   <PropertyGroup>
     <MicrosoftCodeAnalysisCSharpCodeStyleVersion>$(MicrosoftCodeAnalysisVersion_LatestVS)</MicrosoftCodeAnalysisCSharpCodeStyleVersion>
   </PropertyGroup>
+  <!--
+    Consume the latest dependencies from maintenance-packages only when not in source-build.
+    This temporary workaround can be removed after dotnet/msbuild updates its maintenance-packages dependencies and flows them to dotnet/sdk.
+    Without the msbuild updates, roslyn fails. See:
+    https://github.com/dotnet/msbuild/pull/11038
+    https://github.com/dotnet/sdk/pull/45042
+    https://github.com/dotnet/roslyn/pull/76076
+  -->
+  <PropertyGroup Condition="'$(DotNetBuildSourceOnly)' == 'true'">
+      <SystemBuffersVersion>4.5.1</SystemBuffersVersion>
+      <SystemMemoryVersion>4.5.5</SystemMemoryVersion>
+      <SystemNumericsVectorsVersion>4.5.0</SystemNumericsVectorsVersion>
+      <SystemRuntimeCompilerServicesUnsafeVersion>6.0.0</SystemRuntimeCompilerServicesUnsafeVersion>
+      <SystemThreadingTasksExtensionsVersion>4.5.4</SystemThreadingTasksExtensionsVersion>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(DotNetBuildSourceOnly)' != 'true'">
+      <SystemBuffersVersion>4.6.0</SystemBuffersVersion>
+      <SystemMemoryVersion>4.6.0</SystemMemoryVersion>
+      <SystemNumericsVectorsVersion>4.6.0</SystemNumericsVectorsVersion>
+      <SystemThreadingTasksExtensionsVersion>4.6.0</SystemThreadingTasksExtensionsVersion>
+      <SystemRuntimeCompilerServicesUnsafeVersion>6.1.0</SystemRuntimeCompilerServicesUnsafeVersion>
+  </PropertyGroup>
   <PropertyGroup>
     <StaticCsVersion>0.2.0</StaticCsVersion>
     <!-- SDK dependencies (also used in wasm build tests -->
@@ -114,14 +136,11 @@
     <MicrosoftBclHashCodeVersion>6.0.0</MicrosoftBclHashCodeVersion>
     <MicrosoftWin32RegistryVersion>5.0.0</MicrosoftWin32RegistryVersion>
     <StyleCopAnalyzersVersion>1.2.0-beta.507</StyleCopAnalyzersVersion>
-    <SystemBuffersVersion>4.6.0</SystemBuffersVersion>
     <SystemComponentModelAnnotationsVersion>5.0.0</SystemComponentModelAnnotationsVersion>
     <SystemDataSqlClientVersion>4.9.0</SystemDataSqlClientVersion>
     <SystemDrawingCommonVersion>8.0.0</SystemDrawingCommonVersion>
     <SystemFormatsAsn1Version>8.0.1</SystemFormatsAsn1Version>
     <SystemIOFileSystemAccessControlVersion>5.0.0</SystemIOFileSystemAccessControlVersion>
-    <SystemMemoryVersion>4.6.0</SystemMemoryVersion>
-    <SystemNumericsVectorsVersion>4.6.0</SystemNumericsVectorsVersion>
     <SystemReflectionMetadataVersion>10.0.0-alpha.1.24565.3</SystemReflectionMetadataVersion>
     <SystemReflectionMetadataLoadContextVersion>10.0.0-alpha.1.24565.3</SystemReflectionMetadataLoadContextVersion>
     <SystemSecurityAccessControlVersion>6.0.0</SystemSecurityAccessControlVersion>
@@ -130,9 +149,7 @@
     <SystemSecurityPrincipalWindowsVersion>5.0.0</SystemSecurityPrincipalWindowsVersion>
     <SystemSecurityPermissionsVersion>7.0.0</SystemSecurityPermissionsVersion>
     <SystemTextJsonVersion>10.0.0-alpha.1.24565.3</SystemTextJsonVersion>
-    <SystemRuntimeCompilerServicesUnsafeVersion>6.1.0</SystemRuntimeCompilerServicesUnsafeVersion>
     <SystemThreadingAccessControlVersion>7.0.0</SystemThreadingAccessControlVersion>
-    <SystemThreadingTasksExtensionsVersion>4.6.0</SystemThreadingTasksExtensionsVersion>
     <SystemValueTupleVersion>4.5.0</SystemValueTupleVersion>
     <runtimenativeSystemIOPortsVersion>10.0.0-alpha.1.24565.3</runtimenativeSystemIOPortsVersion>
     <!-- Keep toolset versions in sync with dotnet/msbuild and dotnet/sdk -->